Virtual auditory display systems (including for example computer games, virtual reality systems or computer music workstations) create virtual worlds in which a listener can hear sounds generated from sound sources within these worlds. In a computer game, the player hears the sound that he/she would hear if he/she were located in the position of the virtual listener in the virtual world. In a music production system, the composer or sound engineer can use an audio mixing system to create a recording that simulates multiple instruments located at different positions relative to the listener. Similarly, audio-visual systems for home use can recreate sonic environments that mimic real or artificial environments, such as a concert hall or jazz club. These sound processing systems are designed for playback over headphones or over a set of two or more loudspeakers.
In addition to reproducing sound emanating directly from a virtual source, such a system may also process the source signal to simulate the effects of the virtual environment on the sound emitted by the source. One important environmental factor is reverberation, which results from reflected sound paths off objects and boundaries in the environment.
As computer environments and entertainment systems become more sophisticated, it is desired to provide more sophisticated and accurate rendering of the sounds as heard in the virtual environments used by such systems.